Different use of に (は/も)

Question

Recently I came across these two sentences in chapter 6 of Tobira:

天照大神には須佐之男命という弟の神様がいたのですが...

私も変だと思うだけど、でも、私の友達にも結婚式は絶対に教会でしたいと思っている人、結構いるんだ。(here, both the people in the dialogue think it weird that Japanese people would choose to marry at a christian church, which I think contrasts with the opinion of this friend)

My question is about the use of に in these situations: what do they mean or what is their function?

Regarding the first one, I think it means the same as は does alone, but then why use the に?

The second one I find more complicated. I can think of it as meaning "for my friend there are quite a lot of people that want to...", but it does not seem right when seeing the bigger context.

Answer 1

The に means (abstract) location for いる.

In Japanese, いる can be used not only for There is/are... but also for (someone) has..., where someone is indicated by に.

• 部屋に子供がいる There is a child in the room.
• 私に(は)3人の子供がいる I have three children ('Three children exist at me')

For the sentences in question, 天照大神には topicalizes the 'location' 天照大神に; it does not change the meaning, but more often には is used for this case than に alone.

In the second sentence, 私の友達に is slightly different from the above (see the examples below) and means among my friends. It means the same as 私の友達の中に. も add also, so 私の友達にも...思っている人、結構いるんだ means (Not only those you talked about,) also among my friends, there are many people that ...

• 私の友達に(は)弟がいる My friend has a brother
• 私の友達に美容師がいる One of my friends is a hair dresser.

Answer 2

The first に is a に of location/possession. It's the same pattern as アパートに弟がいた。, or 私に本がある。You do often see the possessor indicated with は but I think that conceptually it's not so much that you start with は for possession and then can randomly add に, but instead that you start with に for possession, add は for emphasis, then can drop the に.

The second に tripped me up for a second as well, but I think the confusion actually stems from a sentence-parsing problem. The 私の友達にも bit doesn't belong to the と思っている modifying clause, it belongs to the wider sentence. I.e. 私の友達にも[結婚式は絶対に教会でしたいと思っている]人、結構いるんだ。Basically, "among my friends, there are a lot of people who want to have their wedding in a church." A simpler sentence following the same pattern would be something like "私の友達に外国人が結構います。 Among my friends there are many foreigners."